Selectively operated circuit controlling device



Dec.-21, 1943. A. H. MILLER 2,337,486

SEIJECTIVELY OPERATED CIRCUIT CONTROLLING DEVICE Filed Aug. 29, 1941Sheets-Sheet 1 FIG! INVENTOR AHMIILLER A T TORNEY Dec. 21, 1943.

'A. H. MILLER SELECTIVELY OPERATED CIRCUIT CONTROLLING DEVICE Filed Aug.29', 1941 2 Sheets-Sheet 2 INVENTOP EVA. HM/L'LER (9, %%mfl1 A TTORNEYPatented Dec. 21, 1943 nane SELECTIVELY OPERATED CKRCUET CONTROLLINGDEVICE Albert H. Miller, Bayside, N. Y., assignor to Bell TelephoneLaboratories, Incorporated, New

York, N. Y., a corporation of New York Application August 29, 1941,Serial No. 4%,692

2 Claims.

This invention relates to selectively operated circuit controllingdevices of the step-by-step operated type and which are commonly knownas selectors,

The object of the invention is to provide im provements in a. device ofthe type above mentioned to make the device suitable for use in anemergency signaling system.

A feature of the invention resides in a cam provided in the selector tocontrol the operation of an emergency signal device.

In the drawings,

Figs. 1 and 2 are respectively a top View and a side elevational View ofthe selector with the invention embodied therein.

Fig. 3 is a schematic diagram of a signaling system showing anapplication of the invention.

Fig. 4 is a diagrammatic illustration of a radio signaling system inwhich the invention is found useful; and,

Fig. 5 is an enlarged view in perspective of a portion of the wheel ofthe selector and showing the cam mounted on the wheel and a set ofcontacts operated by means of the cam.

The selector is found useful in selective sig naling systems comprisinga central signaling station and a plurality of substations to beselectively signaled by the central station and provides means forcontrolling the operation of an emergency signaling device ateachsubstation when an emergency signal for all substations is sent fromthe central station.

The improved selector may follow the general form of the selectorillustrated and described in Joseph C. Field Patent 1,343,256, issuedJune 15, 1920, and reference may be had to that patent for anunderstanding of the general form and arrangement of most of the partsand the general manner in which the selector may be operated. Tosimplify the description and understanding of the invention and not inthe sense of limiting the invention to that particular form, it will beassumed that the invention is embodied in a selector of the type shownin the abovementioned patent.

The selector is so constructed and arranged that it may be operatedrapidly and accurately in response to alternating current impulses andcomprises a polarized electromagnetic driving device; a centrallypivoted armature, a stepping or actuating pawl driven by means of thearmature and a wheel operated in an advanced movement by means of thepawl. The wheel carries a wiper contact and is rotated in an advancedmovement to carry the wiper contact into engagement with the desired oneof a group of fixed contacts, the wheel being advanced one step for eachimpulse received by the electromagnetic driving device, A return springis provided in each selector to return the wheel to starting positionand releasable holding means are also provided to hold the wheel invarious advanced positions against the action of the return spring. I

As shown in the drawings 5-5 designate the windings of theelectromagnetic device, ii the centrally pivoted armature which ispolarized by means of the permanent magnet l. Attached to the armature 6is an elongated S-shaped arm ii carrying at its free end a pin 9 and ata point intermedate its ends a pin it, both pins being adapted to engagea pivoted lever 52 carrying at its outer end a stepping pawl :13. Thecoils ii5 and the cores on which they are wound are supported in abracket 19 mounted on a base i. Carried by the supporting bracket is isa frame comprising upper and lower members or plates M and i5 fastenedtogether and between which there is a pin it upon which the lever 82 ispivoted in position to move the stepping pawl l3 into engagement with aratchet wheel i'l mounted on a shaft 18 journaled in the frame members ii and I5. By means of a spring 45 the ratchet wheel I! is normallyretained in a position with a pin thereon (not shown) in engagement witha stop member (not shown) but which is supported on the under surface ofthe plate I i. The stepping pawl I3 is normally held against the stoppin 56 supported on the plate E5, the pawl i3 being normally held inthis position by means of a spring 5! which is attached at one end tothe pawl l3 and at the other to the pivoted lever i2, an adjustable pin52 mounted in a projection of the plate i i limiting the forward travelof the pawl l3. By means of a spring 3 secured at one endto the lever l2and at the other to an arm 36 mounted on the plate t5, the lever i2 isnormally held in the position shown in Fig. 1 and with the stepping pawll3 out of engagement with the ratchet wheel i'i. The pins 9 and Illengage the pivoted lever it upon opposite sides of the pivot axis or pinIii and upon opposite faces in such manner that with each movement ofthe armature ii, in either direction the stepping pawl l3 will cause aone step advance movement of the ratchet wheel ll.

Mounted upon the shaft l 8 carrying the ratchet wheel i? and movabletherewith is an apertured wheel 28 carrying a contact spring 53 in thefree end of which is a contact 2! adapted to cooperate with a pluralityof fixed contacts or, 23 and 25 mounted upon an insulating plate securedto the plate it. Holding pins 28 and 23 carried by the wheel 2d areadapted to cooperate with a holding spring insulatingly mounted on theplate i i. The holding pin is located in a definite position on thewheel 28 while the holding pins 2'? and 23 are made removable so thatthey may be secured in any of the holes d provided in the rim of thewheel 2t, the location of the holding pins 2'! and 28 depending on theparticular code of impulses to which the selector is to be maderesponsive. The spring 35 normally bears against the insulating knob orroller 3i! carried by the lever l2 and is so tensioned or bowed that inthe neutral position of the armature 6 the free end of the spring 3awhich is provided with a curved projection extends inside thecircumference of a circle described by the holding pins 27. 2S and Ellin the movement of the wheel All. As the armature 5 moves, how ever, inresponse to current impulses through the w ndings 5-5 of theelectromagnets. the movements of t e lever 52 will move the projection33 outwardly beyond he periphery of the wheel and when. the ratchetwheel ii is moved by means of pawl 13, in accordance with currentimpulses supplied to the windin s and to a position where one of the pns 2?, or is opposite the projec ion 38. the selector is deenergized,the spring 35 will move inwa. d -y to bring the pro jection 38 nto enagement with that pin to hold the wheel 25 in the position to which ithas been advanced. \A hold ng pawl is prov ded to engage the ratchetwheel ll and prevent dropping back of the ratchet wheel l'l dur the timethat the armature t is traveling from one extreme position to the otherin response to a change in po-- larity of the energizing current.

The wheel 28 may be stepped around to bring the contact 2i intoselective engagement with the fixed contacts 22, 23 and M. Each of thesecontacts may be in control of a circuit including a bell or other signaldevice. The selector therefore be operated to selectively control thesignaling devices served by the fixed contacts 22, 23 and 26.

In the present invention, the wheel is equipped with a cam of particularform and construction and a pair of normally open contact springs ismounted on the selector to be operated by means of the cam.

Selectors of the general type above described and not having theimprovement provided in the present invention are commonly used inselective signaling systems employed in train dispatching. The selectorsare located in substations commonly called way stations of the systemand may be operated by code impulses sent from a central station, thecode impulses being sent by operation of suitable code sending keys orby operation of some other suitable impulse code sending device. Whenthe impulses are sent all selectors connected to the signaling systemoperate to advance the wheels Ell so that the contacts 2i are movedtoward the fixed contacts of the selectors. The impulses are sent ingroups with appreciable pause between each group. The s ector havin itsholding piins arranged for the code signal sent will be finally advancedto a position where the contact El engages one of the fixed contacts 22,23 or 2 5. The other selectors will return to normal position during thepauses between the groups of code impulses. By use of the selectors itis therefore possible to selectively control the operation of signalingdevices at the way stations.

In the present invention a cam Ht is secured to the upper surface of theWheel 2-3 in the se- 5 lectc-r a d is rotated by of the wheel 25engagement with. a knob Ell pro-- e under-surface of a relatively longleaf spring contact 552 of pair of contacts H3. T is i ii? is an inch; etype cam havln an up acting portion lid and a downwardly portion i5 3".The finger portion 5 l 5 siopes downwardly i1 cm the upper end of theportion ii and into engagement with the wheel and is curved to followthe form of the rim of the whee. The lower end of the portion te mhatesin an ly disposed aper i a bolt iii which extends 1'3 aperture in theloot portion l i3 and holes 5 in the rim of the it.) is so mounted onthe line "'on shown in l and 2 to the dotted line pcsit'on shown inthese figures. During this eat, the finger portion H5 is gradually 35moved in successive ste .s the knob Hi and gradually flexes therelatively long spring finger contact 552 into engagement with theshorter spring contact 68 of the pair of normally open contacts 653. hespring contacts H2 and MS as shown in Fig. 3 may be in a local circuitH9 including a source of current supply i159 and a signal device 52 i.

The contacts M3 are insulatingly supported as shown in Figs. 1 and 2 onan angle bracket 122 which is supported by means of the screws on adownwardly extending side portion of the plate M. The position of thecontact springs Eli-l relative to the cam H8 is such that the cam i itwill not only cause closing of the contact H2 against the contact H5,but will also cause upward flexing of the contacts 1! l2 and H3 when thehigh point on the cam i it is brought almost directly under and inengagement with the knob l i l. The wheel 28 has a tendency to rotateback to normal position under action of its return spring 55 betweeneach successive impulse ap plied to the selector. In this briefclockwise movement of the wheel as, the extent of movement is notsuilicient to cause opening of the contacts M3 since the cam Hill is notcarried out of engagement with the knob l l i and the upward flexure ofthe contact H3 under the action of the cam l ill has built up sufficientspring tension in the contacts M2 and M3 to hold the contacts inengagement during the slight return movement of the wheel The localcircuit H9 will therefore remain closed during this brief period.

The cam lid is made with the long sloping finger portion H5 slopingdownwardly in the direction of the forward rotation of the wheel 29 andfollowin the curvature of the rim of the wheel and is so arranged on thewheel 2E? and relative to the knob ill that when the wheel 2&3 isrotated to bring the cam i iii to the position shown in Fi 5, thecontacts H3 will be closed before the cam Hi! reaches its final operatedposition and that from then on until the cam lit reaches its finaloperated position, the contacts H3 will be flexed upwardly toaccommodate the rising form of the cam. It will be seen therefore thateven when the wheel it rotates slightly backward between pulses, and thecam lid, in efiect, slides under the knob i l l, the contacts M3 stillremain closed to keep the local circuit H9 closed and the bell liiistill operating. If the cam i it were not made with the relatively longsloping finger portion i555 and the contacts lit were not flexed by thecam lit, the contacts H3 might open on a slight return movement of thewheel 28 and the local circuit lit would be opened and the bell signall2i would stop rin ing until the cam closed the contacts lit again. Theselector embodying this invention may be used as shown in Fig. 3 in theselective signaling system. In this figure iii and "ii designate linewires extending from a central transmitting or dispatchers station A toa plurality of receiving or way stations B and C. At each way stationthere is a selector '52, the windings 5-55 of which are connected inbridge or the line wires and in series with a condenser l t and twoimpedance coils iii-"l5. Each way station also equipped with a signalingbell l5 under control of the selector thereat and a telephone set llincluded in a normally open bridge of the line A single battery '53 ineach Way station may serve for operating the signal hell it and forfurnishing current for talking purposes. At each way station there maybe additiona signaling devices such as 19 and which may be exactly likethe signaling bell l6 controlled by the selector and operated from thelocal battery it.

At the transmitting station A there is a main battery 55 for supplyingcurrent for operating the selectors at the way stations. This battery isnormally disconnected from the line wires and may be connected therewithby the operation of a relay 53. A pole-changing relay Bl is provided forreversing connections from battery 85 to the line wires. The relays t6and iii are connected in parallel and in circuit with a local battery38, and are controlled by the impulse transmi ters 89, Q9 and ill. Thetransmitter till is for calling w ay station B, $6 for calling waystation C, and 9i for calling both way stations in case of emergency.The transmitters are adapted to rotate in the direction of the arrow andare provided with teeth to control the operation of contact springs 9tand Si in circuit with the pol changing relay Bl. Certain of the teethin the transmitters 89 and lid are blocked out by means of one or bothadjustable cams 9 and 95 to obtain the particular number and combinationof eifective teeth for calling purposes. The free end of contact springer of transmitters lit and 5 is bent downward and carries at theextremity thereof an insulating roller til which, as the transmitterrotates is adapted to ride on top of th cam t5 and separate contacts i iand @l during the time of passage of the cam and the contact spring 523of each transmitter is normally out of engagement with the rotatablethereof and during the revolution of the disc of each transmitter,contact spring 963 is in engagement with the disc maintaining thecircuit of relay t5 closed to connect battery E5 to the line wires 2'9and M. It is to be understood that when potential of either polarity isapplied to the line for a sufiicient interval, the condenser i i-itbecomes charged, whereupon the flow of current through that an emergencysignal is being sent.

the electromagnet coils 5-5 ceases and the selector magnets release,allowing the wheel 20 to return to normal position. These transmitterswill operate to cause the sending of signal impulses divided into threegroups with appreciable pauses between each group of impulses. Upon thesending of these impulses the selectors at the way stations will steptheir wheels 25! around in the direction indicated by the arrows, tomove the Wiper contacts El towards the fixed contacts 22, 23 and 2d. Theholding pins 27 and 2% on the selector at station E are so set that thisselector will reach a contact-making position when the transmitter iii!is operated, the holding pins serving to hold the wheel 26 againstreturn to normal position during the interdi ital pauses between groupsof impulses. All other selectors in the system will return to normalposition during the interdigital pauses when the transmitter 89 isoperating. The selector at way station C has its holding pins set sothat this selector will reach a contact-making position when thetransmitter $9 is operated. All other selectors will return to normalposition during the interdigital pauses. The signaling device it at waystation B will therefore be operated when the transmitter 88 is operatedand the signal device 76 at way station C will be operated whentransmitter as is operated. Other transmitters (not shown) may beprovided at the centra1 station A to selectively cause the selectors atthe way stations B and C to advance to the contacts 253 and 25.

When the transmitter 98 is operated all selectors la in the system willbe operated to step the wheels 2Z9 around as far as they can go. Sincethe transmitter Ql has no cams 9 3 and provided therein and will notoperate to cause interdigital pauses to occur in the series of impulsessent and the impulses sent will be of sufficient number to step thewheels 28 around to bring the cams liil into engagement with the knobsill, the signal devices l2! at all way stations will be brought intooperation to indicate The system, including selectors of this inventionmay therefore be used in selectively signaling way stations from acentral station and in simultaneously signaling all such way stations toindicate an emergency condition.

The improved selector might also be used in a radio system for bringinginto operation signal devices at remote stations to indicate that an SOScall is about to be sent. In this case as shown in Fig. i, a centralstation A might send a radio signal to substations B and C to indicatean emergency condition. Station A in this case would be equipped with atransmitter 9i shown in Fig. 3 and the substations B and C would beequipped with the improved selector i2 and the signal devices IZI, theonly difierence between the systems shown in Figs. 3 and 4 being that inFig. 4 the central station is equipped with radio transmitting apparatusindicated by the box I24 to transmit the emergency signal by radio, andthe substations B and C are equipped with radio receiving apparatusindicated by the boxes H25 and lit to receive the radio signals andcause operation of the selectors Til in accordance therewith. Radiosignals sent to cause operation of the selectors to indicate anemergency might be continued over a relatively long period to insureoperation of the selectors even when storm and other atmosphericconditions are such that radio signaling is diflicult. To

take care of such conditions it is contemplated that the transmitter 9!would be arranged to send the impulses for a long enough time for theinterfering atmospheric conditions to change to a more favorablecondition for radio signaling. It has been found, for instance, thatwhen the signals are continued for about three or four minutes duringstorm conditions the signals will get through from the transmittingstation to the substations at some time during this period. Thetransmitter 9| in this case would be arranged to continue in operationfor a long enough period to insure stepping around of the cam Hi? to acircuit closing-condition for the contacts l H and 9 58 at some timeduring the sending of the emergency signal impulses.

What is claimed is:

1. In a step-by-step operated selector comprising a wheel operatingagainst a return spring for said wheel, and electromagnet means toadvancerotate said wheel in step-by-step movements, in combination, acam mounted on the rim portion of said Wheel and having a long curvedfinger portion pointing in the direction of advance movement of saidwheel, said finger portion following the curvature of the rim of saidwheel and gradually sloping upwardly from the plane or" said Wheel, aset of leaf springs supported above the plane of said wheel and arrangedin normally open contact position, one of said leaf springs beingrelatively long and extending into the path of movement of the higherportion of said cam, said cam being operable to pass part way under saidleaf springs to move said leaf springs into closed contact condition andstill further flex said leaf springs to build up contact pressuretherein, and the slope of the finger portion of said cam and the fieXureproduced in said leaf springs by means of said cam being such that aone-step return movement of said wheel will not release said leafsprings from closed contact condition.

2. In a step-by-step operated selector comprising a wheel operatingagainst a return spring for said wheel, and electromagnet means to ad-Vance-rotate said wheel in step-by-step movements, in combination, anL-shaped cam mounted on the side of said wheel and having an end portionextending normal to the plane of said wheel, a curved finger portioncontinuing from the outer end of said end portion and gradually slopingdownward to the plane of said wheel and in a direction of advancemovement of said wheel, a set of leaf springs supported above the planeof said wheel and having normally open contact points, one of said leafsprings extending beyond the contact point thereon and into the path ofmovement of the higher portion of said curved finger portion of said camand arranged to gradually ride up on said curved finger portion of saidcam when said wheel is advance-rotated to bring said cam under said leafsprings, said cam operating to pass part way under said leaf springs tofirst move said leaf springs into such position that the contact pointsthereof are in closed circuit condition and then still further flex saidleaf springs to build up spring pressure therein, and the slope of saidfinger portion of said cam and the flexure produced in said leaf springsby means of said cam being such that during a slight return movement ofsaid wheel the contact points on said leaf springs will remain in closedcircuit condition due to the follow-up spring pressure developed in saidleaf springs by means of said cam.

ALBERT H. MILLER.

